In his final Twitter message before announcing his resignation, Pope Benedict XVI told his followers: "We are all sinners."
It was posted at 11.12am UK time on Sunday.
The head of the Catholic Church had made history by using social media to spread the word, beating the likes of Justin Bieber for retweets.
His follower count, which had reached 660,000 before he had even tweeted, passed 1.5 million with the news of his shock resignation.
The 85-year-old was pictured tapping away on his iPad before firing off his first tweet, a goodwill message from the Pontifex account.
Sent at 10.28am on December 12, the first tweet received 7,793 retweets and 2,345 favourites in the first 20 minutes.
Despite his impressive follower count, @pontifex did not follow back - sticking to the eight international versions of his own feed.
He posted a total of 34 tweets during his two months on Twitter.